Hospital Variation in Mortality and Ventilator Management among Mechanically Ventilated Patients with ARDS.

Abstract

Acute Respiratory Distress Syndrome (ARDS) is associated with significant mortality. Despite the mortality benefits of lung protective ventilation, adherence rates to evidence-based ventilator practice have remained low and ARDS mortality has remained high. Determine variation in ARDS mortality and adherence to low tidal volume ventilation (LTV) across US hospitals. We identified mechanically ventilated patients with ARDS using data from Philips eICU (2014-2015). We then used multi-variable hierarchical logistic regression models with hospital site as the random effect and patient and hospital level factors as fixed effects to assess the hospital risk adjusted mortality rate and median odds ratio for the association between mortality and hospital site. We then assessed associations between adherence to LTV (defined as 4-8 mL/kg PBW) and hospital risk adjusted mortality rates using Spearman correlation. Among 4441 patients admitted at 110 hospitals with ARDS, the hospital risk-adjusted mortality rate ranged from 19% to 39%, and the MOR for hospital of admission was 1.33 (95% CI 1.25-1.41). Among 3070 patients at 72 hospitals with available ventilator data, 73% of patients had a median set Vt between 4 to 8 mL/kg PBW; hospital adherence rates to LTV ranged from 13% to 95%. There was no association between hospital adherence to LTV and risk-adjusted mortality rate (spearman correlation coefficient -0.01, p = .93). Similarly, among 956 patients who started with a Vt > 8 mL/kg PBW, there was no association between the percent of patients at each hospital whose Vt was decreased to ≤ 8 mL/kg PBW and risk adjusted mortality rate (spearman correlation coefficient .05, p = .73). Risk adjusted mortality and use of LTV for patients with ARDS varied widely across hospitals. However, hospital adherence to LTV was not associated with ARDS mortality rates. Further evaluation of hospital practices associated with lower ARDS mortality are warranted.